Cooking utensil



Patented Dec. 25, 1934 l r i UNITED STATES, PATENT OFFICE Albert L.Clapp; Danvers, Mass.

No Drawing. Original application March 12,

1926, Serial No. 94,329. Divided and this application February 21, 1929,Serial No. 341,849

4 Claims. (CL 53-6) In my application Serial No. 94,329, filed tivelyrigid material, which is g'reaseproof, fire-, March 12, 1926, of whichthe present case is a p o a d Water-resistant. division, I havedisclosed a composition of matter While in temper, the material may'beformed, comprising fibrous material and setting or hardfor example, intobaking utensils,; suchas cake- 6 ening compounds, wherein such compoundsare pans, pie pans, and the like, by stamping blanks s present in suchquantities as fully to saturate or cut from the sheet material, whichafter setting permeate the fibrous material, and in which the areadapted for use as substitutes for utensilsfibrous material is presentin closely interielted made from sheet metal. Such utensils retaincondition, having preferably the closely inter-v t eir f u d ba t mp ates and 10 felted conditions such as is produced by paperfiaVOl" f thfood is n t deleteriously flfieeted making methods. Such a compositionby the use Wh being ba Since there are n0 maIOdOrS, of suitablesettingor hardening compounds may which arise f m the u e even though eapossess certain desirable r -ti h a being bonization of the cellulosefibers does-take place. water-, .greaseand fire-resistant, and beingEven When Subjected t the full blast Of a Bunsen mouldable under certainconditions. This appliburner fl h pan retains its form, althou 15 cationis a division of my application hereinbefore a decomposition andcarbonization of the celluidentified, and relates to articles, andmorepar- 10810 fi results, t h W t e o mation of ticulai'ly co kin t lmade from t carbon dioxide. The utensils, moreover, while not position.p J perfectly waterproof, are sufficiently waterproof If asbestos betreated with sodium silicate, parresist d s t t o b r u r e ee 20ticularly in the presence f lime, a plastic comb a er u n i have b u iclto pound results, which sets to a rigid, g'reaseproof bakingtemperatures, y a quit p and. fireproof conditions The set composition,Since Such baking utensils ay be p however, is of low strength andconsequently is e m ally h y be used in Place not suitable for formationinto articles. I have usual baking pe s ade o metal, a d' baked 5-found, however, that if asbestos fiber is employed oods be retainedtherein afte ba thus avoidtogether with cellulose fiber and then formedon ing the ss ty of th usual pap plat s t a paper machine, a sheet ofsuificient strength is which the pies other baked materials areproduced, which when treated with sodium silimonlyltrensferred after bain Th y h serve cate may'thenbe formed into various articles a double i0 having certain desirable characteristics. To Produce Sheet mate ial ae or o In accordance with the present invention, as tion into Variousarticles, I may, for example, bestos fiber and wood or other cellulosicfiber P aS fOHOWS- ,SiXty Parts of d fi e are intermixed by the usualbeating operation, and 40 Parts Of asbestos fiber are P d in t epulverulent lime bein dd d d incgrporated beater engine and suificientwater is added toen- 35 into the pulp while it is being beaten. The pulpSure circulation. The fibers are thorou h y inis then, sheeted on apaper-forming machine, and termixed by heating for about twenty minutes,

dried, The dry sheet i passed t a bath f during which time about 10% to15% lime, based,

sodium silicate and is permitted to become 0n the dry Weight of fib iSadded to the beater thoroughly saturated with the solution,whereengniler The pulp is h run OE and Sheeted on upon the excess sodiumsilicate is expressedfrom cylmder a Fourdnmer machine and the the sheetand the sheet is allowed to stand or formed is dried' The dtied P? orsheet is passed condition until it has been reduced to the proper l bathof sodmm t of about 20? temper or consistency for moulding into articlesBaume produced as by mlxlng equal parts by ht of a solution of sodiumsilicate (60 5 without tend ng to disintegrate. While in such welgtemper, it may be bent and Stamped into Various Baume) and water, andispermltted to become articles withoutbeing cracked or broken, and insaturated thoroughly therewlth' The excess 1 d'um sil'cate is removedfrom the she t b this respect behaves somewhat like ductile sheet i ittrllrough Squeeze r011s ypass 50 t such as sheet 1 1 the 1ike' T Thesodium silicate acts upon the asbestos and m k h formgd 1S finally dned:whlch y h appears to destroy the fibrous characteristic facilitated byplacin it in a Warm, dry atmesthereof, producing a plastic, more or lessgummy ph oriby wm a dry a t upon, composition throughout the sheet,which bewhereupon a permanent harden ng or setting of haves in somerespects like Portland cement, as

the material takes place, resulting in a comparait becomes set. .I

Immediately after passage through the sodium silicate bath, the sheet isweak and flabby, and does not successfully permit of article formation,but upon standing for a period it undergoes a change in temper and maybe successfully subjected to forming operations. While in suchcondition, the sheet may, for example, be rolled up, or unrolled, andthere islittle, if any, tendencyfor successive .convolutionstov becomeunited unless subjected to pressure. The

sheet may be kept in temper when subjectedto humid conditions, for somehours, after which a hardening of the material takes place even underconditions of high humidity. i

While in temper, the sheet materlal may be stamped into such articles asbaking pans, or formed into cans, boxes, tubes and other prod ucts. Insuch condition, the material also possesses the property of beingself-sealing, i. a, two layers of the material maybe united without theuse of ahextern'al binder or-adheslve, by exerting sufiicient pressureon the two layers and then'allowin'g a hardening of the material to takeplace, which maybe facilitated by subjecting it to warm,;dry conditions.'By this means, the layers are caused to unite, the hardening of thematerial effecting a permanent union between the-layers. In forninglsuch articles as boxes, cans'andjtubes from thejfmaterial, thisproperty is veryadvantageous, inasmuch as thejoints or seams maybeeffected by the application of pressure on the abutting edge portions ofproperly cut blanks, and without employing any adhesives.

'Whenthe'material has iig'idified or set, itis greasepro'of f andoilproof, and consequently is admirably adapted foruse' in the formationof such articles as paint and'oil containers, baking pans, and the likeThus, for example, in'baking cakes, the surface of-the bakingpan may begreased without danger ofpenetration through the 'utensil, thuspermitting ready removal of the baked material.

If desired, the grease-resisting property of the container may be"enhanced by applying a coating of glue or other greaseproofing materialthereto. In addition, sizing 'or waterproofing agents, as in the form ofinsoluble soaps or wax, may also be applied, eitheralone or togetherwith the greaseproofing agent, to the surface of the material Suchagents, however, are preferably not employed when the material is to beformed into articles which are to contact with foodstufis,inasmuch asthetaste of the food might bedeleteriously affected. 7

- Sheet material made as herein specified may be formed into thin sheetson a papermaking machine,-havingfa thickness of as low as 5 1306 pointsor thousandths of an inch, although for ordinary article formation thematerial is preferably-formed to a thickness of about 'lto 8 points, orgreater. Forforming tubes or conduits, however, a sheet of considerablethickness maybe produced and then wound, although a relatively thinsheet may be wound upon a man- 'drel'and the successive convolutions besufliciently-pressed together to ensure a union therebetween and asubstantiallyhomogeneoustube produced, which, when permitted to harden,has all the "successive convolutions permanently united. I

In addition, the sheet material is very light, amounting to about 1/12to 1/15 the weight of sheet tin of the corresponding caliper." 3

Articles of substantial thickness may also be formed by winding orotherwise superposing seV- eral layers of the sheet material while intemper, and then uniting and moulding the layers into the desiredarticles under sufiicient pressure to effect a permanent uniontherebetween. By this means, after the setting or hardening of thematerial has taken place, a dense, hard and stony material is produced.

While the incorporation of pulverulent lime into the stock prior tosheeting on a paperforming machine may be dispensed with, yet I find itpreferable to use lime. The lime also reacts with the sodium silicate toform a hardening compound, and acts to effect a better conditioni n'g orcontrol of the temper of the mate'- rial for forming operation, aidingin producing aproduct possessing the required characteristics. When limeis not used in the furnish, however, thesheeted material after passagethrough the sodium silicate bath is more or less flabby and difficult toform without collapse and br akage of thesheeueven after tempering. Thelime in addition ensures a better absorption and retention of the sodiumsilicate within the'sheet, rather than permitting a surface absorptiononly; and also controls the rate of setting of the mixture of asbestosand sodium silicate; and hn-- parts the physical characteristics desiredin order to mould or stamp the sheet, and also certain of :the desiredcharacteristics in the sheet afte hardening.

' The use of cellulosic pulp, e. g., sulphite pulp or mechanical woodpulp, together with the asbestos fiber in forming the sheet, however, isindispensable. Not only does the cellulosic fiber impart strength andbody to the web during paper-forming operation and production, butserves as an excellent absorbing medium to retain sufiicient sodiumsilicate within the sheet to ensure characteristics desired in thefinished product.

In certain instances, but with disadvantage, however, the use ofasbestos in the furnish may be dispensed with and substituted by otherhardening material. In such instance, the percentage of lime or otherequivalent compound which reacts with sodium silicate to form ahardening compound and which is incorporated into the stock prior tosheeting on a paper machine or otherwise forming the fibers into aninterfelted material, is raised to about 20% or more. In order to impartgreater body to the material, especially when it is to be employed whereits fireproof property is of prime importance, in addition to the lime,certain inorganic fillers, such as pulverulent kieselguhr and cellite,may be incorporated into the pulp prior to its formation.

While I have described a specific example of procedure which may befollowed in producing a sheet suitable for a variety of uses, andcertain articles of manufacture which may be produced therefrom, itshould be obvious that this is by way of illustration only and thatvarious modifications of procedure may be employed and that the materialmay be put to other use for which it may be found suitable. Forinstance, in the example given, I may employ 60 parts of asbestos fiberand 40 parts of cellulose fiber, or other proportions of asbestos andcellulose fiber. In general, however, I find it preferable to employapproximately equal parts of the two fibers. The proportion of lime usedis also subject to variation, and while preferably employed in theproportions stated, may be somewhat increased or se of.

decreased, and may, if desired, be replaced in part or entirety by otherconditioning agents, e. g., certain pulverulent alkaline earthcompounds, such as limestone, magnesium oxide, magnesium carbonate, orcertain other compounds, such as manganese dioxide.

Where the material which is capable of reacting with the sodium silicateto form a hardening compound is first incorporated into the fibrousmaterial prior to formation, and such fibrous material formed intointerfelted material, and then saturated with a solution of sodiumsilicate, the setting or hardening compound permeates or saturates thematerial as a continuous, coherent body. Such a process cannot beconsidered to be equivalent in any sense to a process wherein both limeand sodium silicate are added to fibrous material prior to formation,this latter process merely resulting in a filler being precipitated onthe fibrous material in a pulverulent condition but without carrying theinterfelted fibrous material and permeating or saturating it, as is thecondition in the present process. Nor is the material producedequivalent to the product prepared by treating or immersing interfeltedfibrous material in a bath of hardening or setting compounds, as in acement paste, and then permitting the material to rigidify.

It will be noted that according to the present invention, two agentswhich react together to form a hardening or setting compound areemployed, and that this reaction is produced within the previouslyfelted fibrous material, this being effected by incorporating one ofthese agents with the pulp prior to interfelting it, and then treatingthe interfelted material having the agent therein with the hardening orsetting reagent.

Having thus described the nature of my invention and described a way ofmaking and using the same, although without attempting to set forth allthe forms in which it may be made or all the modes of its uses, what Iclaim is:

1. A cooking utensil formed from a normally inflammable absorptivematerial rendered resistant to heat at baking temperatures byimpregnation with a fireproofing substance which will not exude atbaking temperatures and coated on its inner surface with a waterresistant material which will penetrate the body of the utensil atbaking temperatures.

2. A cooking utensil formed from a normally inflammable absorptivematerial rendered resistant to heat at baking temperatures byimpregnation with a fireproofing substance which will not exude atbaking temperatures and coated on its inner surface with parafiine ofrelatively high melting point.

3. A cooking utensil of the character of a pieplate, baking pan or thelike, comprising a molded structure of interfelted fibers containing,besides cellulose film, at least about 40% asbestos as a componentimparting heat-resistance thereto, said structure being impregnated withand stiffened by sodium silicate.

4. A cooking utensil of the character of a pieplate, baking pan or thelike, comprising a molded structure of interfelted fibers containingboth cellulose fiber and asbestos fiber, said structure beingimpregnated with and stifiened by sodium silicate.

ALBERT L. CLAPP.

